Medical treatments have conventionally been carried out in which therapeutic medications are formulated as infusions which are administered intravenously. Infusions employing therapeutic medications in the form of anticancer agents, nutrients, and the like must typically be administered in high dosages. Furthermore, where a plurality of medications are combined, each infusion must be administered in order, and the total administration dosage is quite high. On the other hand, as administration of infusions continues, because a sudden rise in the concentration of a drug within the blood increases the risk of occurrence of anaphylactic shock, cardiac arrhythmia, and other such side effects, there is a need for physicians and nurses to carefully continue to adjust infusion administration dose while monitoring the condition of the patient. However, carrying out administration by adjusting amount by means of injection is difficult, and as administration time goes on and the number of administrations increases, the patient experiences an increasing amount of bodily pain and is placed under an increasing amount of stress. For this reason, intravenous drip infusion is widely used as a technique for easily and continuously administering infusions to patients intravenously. During intravenous drip infusion, an infusion set is employed as medical equipment for causing a container having an infusion sealed therewithin to be connected to an intravenous drip needle that has been inserted within a blood vessel of the patient.
Infusion sets in general use conventionally employ soft tubing to link the container having the infusion sealed therewithin with the intravenous drip needle, a mechanism employing a roller clamp and a drip chamber being provided midway along said soft tubing. This is so as to make it possible to adjust the administration dosage of the infusion by causing the soft tubing to be pressed on to an appropriate degree at the roller clamp while measuring the amount of the infusion that is being delivered per unit of time at the drip chamber. In addition, infusion sets have moreover been proposed which make it possible to link a plurality of containers having infusions sealed therewithin by using a mixing region and/or Y-tubing midway along said soft tubing to split it into multiple branches to accommodate medical treatment in which a plurality of infusions are continuously administered in sequence (see Patent Reference No. 1 and Patent Reference No. 2).
The foregoing proposed infusion sets are used at the patient's bedside, a plurality of containers being linked and suspended from an IV stand. However, with such an infusion set, because the distribution of weight is upset as administration causes the amount of the infusion to decrease, there has been a risk that this can cause the IV stand to fall over, for which reason there has been a need to pay careful attention at the bedside and to, whenever required, adjust the locations from which the infusion set is suspended, as a result of which there has been a need for improvement.
Furthermore, where a plurality of anticancer agents were administered in the form of infusions, particular attention has been required to avoid mixture of solutions for which mixture is contraindicated and to see that administration is carried out in the correct order. Because the type and number of therapeutic agents are different for every patient, infusion sets must be prepared that are reassembled in correspondence thereto. However, it is often the case that the containers employed for infusions have similar external appearance. For this reason, mixups with respect to the order in which spikes pierce containers, confusion as to which infusion line should be used for different anticancer agent solutions, mistaken order of administration, and other such accidents can easily occur. Efforts have therefore been made to prevent accidents due to human errors by applying labels to the various containers at the time that the infusions are prepared, attaching written warnings, and so forth to clearly specify administration procedure, and to make the various containers recognizable, to establish standard procedures for use specific to each of the various infusion sets with their many different constitutions, to publicize this in advance, and carry out training and so forth, but the situation remains unchanged and misidentification by the operator can still occur, as a result of which there has been a need for improvement.
Furthermore, to prevent the infusion from leaking outside the blood vessel during intravenous drip infusion, it is necessary for the patient to remain as still as possible. However, because anticancer agent solutions require at least 3 to 5 hours for intravenous drip infusion, and in some cases can require extremely long times that may be as long as on the order of 48 hours, the patient will have no choice but to at some point during the course thereof go to the toilet, eat a meal, or perform some other physiological activity. The patient must therefore, while continuing to receive the intravenous drip infusion with the intravenous drip needle still stuck in his or her arm, or after closing the roller clamp and reducing the drip rate, or temporarily shutting off and interrupting the drip, or the like, move together with the IV stand, linked to which is the infusion set from which the container having the infusion sealed therewithin is suspended.
However, because the structure of conventionally proposed infusion sets has been such as to make upsetting of balance and twisting of tubing or the like unavoidable, even where the patient, physician, and nurse paid adequate attention, tension acting on the infusion set and/or intravenous drip needle has tended to cause occurrence of pain at the location where the drip infusion is inserted and/or other such bodily pain to the patient, and in the event that the intravenous drip needle that is inserted beneath the skin moved, causing anticancer agent solution to leak outside the blood vessel, or there was further tension or forcible twisting that acted thereon, there has been a risk of occurrence of accidents in which the intravenous drip needle could become dislodged from the arm of the patient, causing an extremely large amount of stress during use.
Moreover, with infusion sets employed for intravenous drip infusion, priming operations are carried out in which an infusion is used in advance to adequately remove air in advance from the soft tubing, and it is necessary to pay adequate attention to ensure that air bubbles originating from such air are not allowed to enter the patient's blood vessel. However, with such conventional infusion sets, it is sometimes the case during priming that an infusion may leak from the tip of the needle at the downstream-most end of the infusion set, and where infusions are used that employ anticancer agents or other such dangerous drugs in which powerful drugs and/or radioactive isotopes are employed, because there is a possibility that physicians and nurses could be exposed to such dangerous drugs, and moreover, that there could be occurrence of an accident in which a hospital room or a hospital wing becomes contaminated, there has been a need for a strategy to prevent such accidents.
An infusion set has therefore been proposed that adopts a strategy to reduce the likelihood of leakage of dangerous drugs to the outside environment by splitting the region upstream of the drip chamber into multiple branches to establish two switchable priming flow paths, a shutoff clamp being arranged below the drip chamber and one of the priming flow paths being employed to carry out initial priming with an infusion having a relatively low level of the dangerous drug, and the priming flow path thereafter being switched, the shutoff clamp below the drip chamber being closed, and the other priming flow path thereafter being used to carry out priming of the remaining priming flow path with an infusion having a relatively high level of the dangerous drug (see Patent Reference No. 3).
However, while it may be true that the risk of contamination during initial priming is relatively low, the structure of the foregoing proposed infusion set is such that it permits leakage of the dangerous drug from below, and so from the standpoint of whether it adequately prevents leakage of dangerous drugs to the outside environment, there has been a need for further ingenuity. Furthermore, because the structure of the foregoing proposed infusion set is such that terminal portions of the infusion set are open, operations have been complicated inasmuch as there has been a need to exercise care with respect to procedural discharge of physiological saline solution or other such solution used during priming from said terminal portions, and inasmuch as there has been a need for priming, which itself comprises multiple procedural steps, to be carried out twice, and so forth. In addition, with the foregoing proposed infusion set, even where adequate care is exercised with respect to procedural discharge of liquid, there is a risk of occurrence of damage to equipment and/or contamination of the hospital room interior as a result of unintentional spillage of the physiological saline solution that is discharged therefrom onto the infusion set, the stand, the equipment used to carry out intravenous drip infusion, and/or the floor of the hospital room, and so there has been a need for even further ingenuity.
Moreover, with the foregoing proposed infusion set, where more than two types of infusion are to be employed for intravenous drip infusion, it has been necessary to remove the container having sealed therewithin the infusion pierced by the upstream spike and to swap it for a container having the new infusion sealed therewithin, or to detach the infusion set from the intravenous drip needle and replace it with a different infusion set. However, there has been occurrence of contamination during swapping, and movement or the like of the intravenous drip needle or tension on the intravenous drip needle during swapping or replacement operations has resulted in increase in the risk that anticancer agent solution will leak outside the blood vessel. In addition, there has been occurrence of pain at the location of the drip infusion and/or increase in other such bodily pain to the patient, and there has also been increase in the likelihood of occurrence of accidents in which the intravenous drip needle moves, increasing the stress that is placed on patients, physicians, and nurses, and requiring further ingenuity and attention.